Of all the athletes expected to compete in the 2012 Olympics, swimmer Michael Phelps remains the best known in the United States. Hands down. No questions asked - even if Phelps hasn't even been his country's best swimmer the past two years (hello, Ryan Lochte).

And sprinter Usain Bolt of Jamaica remains the best known in the rest of the world. By far. Not even close.

Why? I'll explain later.

The relative stature of Phelps and Bolt -- each a transcendent star of the 2008 Beijing Olympics -- is among the conclusions made clearer than ever by the results of 2011 world championships.

In the year before the Olympics, world meets in every sport become closely scrutinized as insights into what might happen at the Winter or Summer Games a year later -- including where media focus will be.

Only a few championships remain in sports that hold some interest for U.S. fans: wrestling began Monday in Turkey; boxing starts Sept. 22 in Azerbaijan; and the most closely watched, gymnastics, runs Oct. 7-16 in Tokyo.

In both wrestling and boxing, the world meets are not only about winning medals but also earning places at next year's Summer Games in London.

The top six finishers in each Olympic weight class at worlds get a spot for their countries -- as Greco-Roman athlete Justin Lester of Akron did Monday by finishing fifth in the 145.5-pound class; the top 10 boxers do the same in all but the two heaviest classes, where it is the top six.

(There are other ways to qualify later, but most do it via world finish).

*And now to Usain vs. Michael.

The difference in global renown between Phelps, the greatest swimmer in history, and Bolt, the fastest sprinter in history, is as simple as the difference in the inclusiveness of their sports.

Swimming remains a white bread sport. Not a single black athlete won a medal in the 40 events at the 2011 world championships. Only 20 countries accounted for the 120 medals, just one nation from Africa (South Africa, three bronze) and one from South America (Brazil three).

The spread is even more limited in events that are on the Olympic program, since two of Brazil's medals and two of South Africa's came in 50-meter events contested only at worlds.

Now for track and field. Forty-one countries won medals in the 47 events at the recent worlds. (All are on the Olympic program).

An African nation, Kenya, was third in golds and total medals. Seven African countries, as well six Caribbean island nations, and two South American nations won medals. A majority of the gold medalists were black athletes from six different countries.

The international swimming federation's attempts at diversity have added up to giving spots -- nearly all in the 50 and 100-meter events -- to athletes who are hopelessly overmatched.

For example: Sixty-seven of the 107 entries in the men's 100 free finished two to 28 seconds behind the leading qualifier.

All those stats are just a way to make a simple point: most of the world doesn't give a flying fish about swimming.

Nearly all the world cares about its fastest man.

*USA men's rowing now has not won a world championship medal in an event on the Olympic program since the Beijing Games. It's the worst drought leading up to an Olympics since 1977 through 1979, which was followed by the U.S. boycott of the 1980 Games.

Most embarrassing part of this year's worlds: The U.S. did not yet qualify for a spot in the men's eight at the London Olympics. The eight finished second in the consolation final.

The USA can still qualify an eight at the Lucerne International Regatta next May, when the last spot will be allocated.

The U.S. has not been without an eight in the Olympic field since 1912, when it did not enter by choice. The eight won the lone U.S. men's medal (bronze) at the 2008 Summer Games and gold in 2004 -- its 12th Olympic title.

For the women's eight, the story is exactly the opposite. They added a fourth straight world gold to the Olympic title won in 2008. That's what you would call rowing merrily down the stream.

*The gymnastics worlds also serve as a qualifying event for teams and individuals.

More significantly, they will decide who is the USA's most watched female athlete -- or athletes -- heading into the London Games.

If Jordyn Wieber repeats the impressive all-around performances she had at the American Cup and the U.S. Championships, look for the 16-year-old Michigander to have most of the spotlight on her. If not, everyone will be watching Dancing With The Stars champion -- and 2008 Olympic all-around silver medalist -- Shawn Johnson in her comeback after two years off and knee surgery.

Unless, that is, 2008 all-around champion Nastia Liukin does a Plushenko (and maybe a Yurchenko) and comes back after nearly three years off following the gold medal.

Plushenko lost the 2010 Olympic gold to Evan Lysacek by an eyelash.

Odds are that the closest Liukin will get to doing gymnastics in London is the flip she performed Tuesday in front of Big Ben as part of a "Britain Bound" promotional tour.